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8.0 REPLACEMENT UNITS
To prevent failure of a new condensing unit, the existing evaporator tubing system
must be correctly sized and cleaned or replaced. Care must be exercised that the
expansion device is not plugged. Test the oil for acid. If positive, a suction line filter
drier is mandatory. For new and replacement units, a liquid line filter drier should be
installed and refrigerant tubing should be properly sized.
9.0 INTERCONNECTING TUBING
9.1 VAPOR AND LIQUID LINES
Keep all lines sealed until connection is made.
Refer to Line Size Information in Tables 2 through 4 for correct size and multipliers to
be used to determine capacity for various vapor line diameters and lengths of run.
The losses due to the lines being exposed to outdoor conditions are not included.
The factory refrigeration charge in the outdoor unit is sufficient for 15 feet of inter-
connecting lines. The factory refrigeration charge in the outdoor unit is sufficient for
the unit and 15 feet of standard size interconnecting liquid and vapor lines. For dif-
ferent lengths, adjust the charge as indicated below.
1/4” ± 0.2 oz. per foot
5/16” ± 0.3 oz. per foot
3/8” ± 0.5 oz. per foot
1/2” ± 1.0 oz. per foot
9.2 MAXIMUM LENGTH OF LINES
The maximum length of interconnecting line is 150 feet. Always use the shortest
length possible with a minimum number of bends. Additional compressor oil is not
required for any length up to 150 feet.
NOTE:
Excessively long refrigerant lines cause loss of equipment capacity.
9.3 OUTDOOR UNIT INSTALLED ABOVE INDOOR COIL
Keep the vertical separation between coils to a minimum. However, the vertical dis-
tance can be as great as 120 feet with the condensing unit ABOVE the indoor coil.
Use the following guidelines when installing the unit:
1.
DO NOT exceed 120 feet maximum vertical separation.
2.
Expansion Valve Coil:
a. The vertical separation can be greater than the value in Table 3, but no
more than 120 feet.
b. No changes are required for expansion valve coils.
3.
Always use the smallest liquid line size permitted to minimize the system
charge.
4.
Table 3 may be used for sizing horizontal runs.
9.4 OUTDOOR UNIT BELOW INDOOR COIL
Keep the vertical separation to a minimum. Use the following guidelines when
installing the unit:
1.
DO NOT exceed the vertical separations as indicated on Table 4.
2.
Always use the smallest liquid line size permitted to minimize system charge.
3.
Table 4 may be used for sizing horizontal runs.
9.5 TUBING INSTALLATION
Observe the following when installing correctly sized type “L” refrigerant tubing
between the condensing unit and evaporator coil:
!
CAUTION
When coil is installed over a finished ceiling and/or living area, it is
recommended that a secondary sheet metal condensate pan be
constructed and installed under entire unit. Failure to do so can result
in property damage.
